let buffer=new Buffer('abc\r\nddasdfafd\r\ndfaerewtwert');

function bufferSplit(buffer, delimiter){
  let arr=[];
  let n=0;

  while((n=buffer.indexOf(delimiter))!=-1){
    arr.push(buffer.slice(0, n));
    buffer=buffer.slice(n+delimiter.length);
  }
  arr.push(buffer);

  return arr;
}

console.log(bufferSplit(buffer, '\r\n').map(b=>b.toString()));
